The spectrum of opportunistic filamentous fungi present in the CBS culture collection.

The mould collection of the Centraalbureau voor Schimmelcultures, Baarn, The Netherlands, was screened for isolates originating from warm-blooded animals. The range of species indicates that distribution of clinically relevant, pathogenic or opportunistic strains over the fungal kingdom is non-random. Some opportunistic fungi possess adaptations to life under hostile environmental conditions, enabling them to survive inside the human body. Presence of melanin or carotene seems to be an important virulence factor. Opportunistic fungi which sporulate in submersion are able to disseminate or cause severe local mycoses when the aspecific immune system of the host is impaired. Mycoses caused by a few dimorphic fungi, mostly in their natural ecological niche living in association with vertebrates, are promoted by specific immune deficiencies.